Fuel system tune-up

[Fox2506]

Getting ready to do some fuel system TLC. Having a couple issues I'm hoping to resolve in the process.

*Stubborn warm starts (after shutting off about 10-30 min). Someone told me this is leaky injectors, so I picked up a new set.

*Strange exhaust smell. I've never smelled anything like it so not sure what to compare it to. I suppose it smells like bad gas, but it doesn't change with fresh fuel. Pretty thick smell too, wafts into the cabin at stops. Looks like a PO replaced the exhaust at some point, so no idea what condition the cat is in. No smoke of any kind.

The inside of my gas tank is very rusty, so I plant to drop it and clean it up. Then replace the filter etc...

Given those issues specifically, what else should I look for? O2 sensor, other sensors?

[danf]

Is there a black ring around the exhaust tip?

If the o2 sensor has never been changed it's probably bad.

If you have aftermarket headers, you'll have to install a heated o2 sensor at the collector to get any sort of sane readings.

For hard to start when warm, it may not be a fueling issue - the igniter or coil tend to show these symptoms when they start going bad. You'll have to test them to figure out which one it is. I just replaced an original 37 year old coil for example, and it had hard starting issues. It fixed it. But diagnose it first!

[Fox2506]

Oh damn. Looks like igniters are out of stock everywhere if I do need one.

[danf]

Well, do some testing...

I tested my coil when it was warm and the primary windings had a resistance of almost 10x the specification.

For the o2 sensor, that won't affect starting but will affect mileage.

[Fox2506]

Finally got around to working on this.

Tested the coil and igniter going by the repair manual I have. Everything seemed to check out, but while I was in there I just threw in a new coil. The warm start hesitation seems to have gone away, but I haven't gone on a full test drive to be sure yet.

I moved on to the exhaust smell issue. I checked timing which looked like it was 3 BTC so I bumped it to 5 BTC. While the diagnostic plug was jumped I went ahead to get fault codes but there were none.

While running in the garage it definitely put out a faint white-ish haze and the smell burns the eyes and throat very slightly. But the smell is odd, I can't say I've smelled it before working on cars. I plan to check the spark plugs and do a quick compression test next.. then change the fuel filter, since I don't think I've ever done that yet.

Edit:
troubleshooting section says to check the idle speed if there is an "unpleasant odor". I think my idle yesterday was way low at 500

[ozzie]

Is it a sickly sweet smell? Or maybe more like rotting eggs?

[Fox2506]

No rotten egg smell. Maybe a tinge of sweet. It smells kinda like gas, but musty/stale and mildly irritating to senses.

It seems like it has gotten a little better since correcting the timing and poking around in the engine bay some. As of yesterday, my idle is right at 750, a little rough, but I have plenty of power.

My gas tank is full of rust so I plan to drop it and refresh the fuel system and see what that does.

[ozzie]

White smoke and a sweet smell could be coolant from a blown head gasket, and these are known to blow them near the #4 fire ring. Might be worth investing in these to check:

https://www.harborfreight.com/combustion-leak-detector-64814.html
https://www.harborfreight.com/combustion-leak-detector-fluid-56154.html

[Fox2506]

I don't think I have any symptoms of coolant leaks. No smoke of any kind at any time, just a haze in the garage.

I got around to dropping the gas tank. Lots of crusticles came out when I drained the gas. Pump strainer has some junk in it. Filled the tank with white vinegar, and cleaning up the undercarriage this week.

My pump is an OE type. I neglected to check my fuel pressure before starting. Wonder if its worth just replacing it while I have the tank out, since now I know rust particulates have been going through it. $120 unit.

[sirdan]

I'd replace it but make sure it's a quality pump so it lasts a long time.

[Fox2506]

Yea I ordered one..

[Fox2506]

Is the pressure side fuel hose (female threads at both ends, 9" long, connects body line to fuel pump) available anywhere, or cross-referenced?

[Fox2506]

Just an update.. Totally restored the fuel tank with as many new parts as possible. Cleaned out tons of varnish debris and rust and sealed it with POR15 tank sealer. Changed the fuel filter and the old one had gas in it that looked like Yoohoo. Installed the EGR delete kit. Cranked right up and runs great with a perfect idle. I think the exhaust smells a little better but still bad. Looking at the catalytic conv next.

Any input on a fuel system cleaner that's good/safe for this system?

[1933beer]

I am interested in egr delete kit. I like to put sea foam in the tank each spring for the fuel system.

[Fox2506]

I am interested in egr delete kit. I like to put sea foam in the tank each spring for the fuel system.

https://www.lceperformance.com/EGR-Block-Plate-Kit-22RE-RET-EFI-Only-p/1016039.htm